A Rare Case of Moyamoya Disease in a Hispanic Woman: Unveiling Non-Asian Ethnicity and Atypical Risk Factors

BACKGROUND Moyamoya disease is a rare and progressive cerebrovascular disorder caused by narrowed or blocked arteries supplying the brain. First described in Japan, the disease's incidence is higher in Asian countries and primarily affects children, although adults can also be afflicted. Following a literature review, very little was found regarding non-Asian ethnicities and the lack of typically associated risk factors that are known correlates of Moyamoya disease. CASE REPORT We present the case of a 41-year-old Hispanic woman with a history of type 1 diabetes mellitus and asthma who presented to the Emergency Department with concerns of recurrent transient episodes of left upper extremity weakness and paresthesia followed by confusion. The patient's blood pressure on arrival was 215/134 mmHg, and heart rate was 124 beats per min. Computed tomography of the head was unremarkable, but a computed tomography angiogram of the head demonstrated several areas of severe and bilateral stenosis with radiographic appearances, suggestive of Moyamoya disease. Magnetic resonance imaging of the brain would later illustrate two 6×2-mm ischemic infarcts in the right posterior centrum semiovale. CONCLUSIONS Moyamoya disease in the non-Asian population is rarely reported. We present a case of this condition in a patient of Hispanic ethnicity. Although it is generally considered a non-atherosclerotic disease, some literature suggests that atherosclerotic disease may also contribute to the development and possible acceleration of clinical features of Moyamoya disease. Given our patient's risk factors, we postulated that our patient's presentation was likely multifactorial, with both non-sclerotic and atherosclerotic disease.